Kevin Langley Jr.

Add widgets on a post by post basis by using a new interface directly on the post edit screen.
Filter to set the post types the Post Widgets plugin should load on post_widget_post_types

Voce Post Widgets

A better interface for managing your widgets.

Steph Wells

Use any of your Contact Form 7 Forms in your sidebars. You can even style it from the widget options. This will also work with any other shortcodes that only work in posts. Just insert the shortcode (ie [contact-form 1 “Contact form 1”]) in the ‘Contact Form 7 tag’ text field. Leave styling options blank in order to style from your theme’s css.
note: rounded corners do not work in Internet Explorer… Surprise! Get a different browser! 
another note: Use 6 digit hex colors for better results

Contact Form 7 Widget

Use your Contact Form 7 forms and other shortcodes in your sidebars.

Voce Post Widgets vs Contact Form 7 Widget